Lower extremity peripheral arterial disease (PAD) affects 12% of men and women over age 65 and is associated w/ risk of cardiovascular death. PAD can be diag-nosed and quantified in the ambulatory setting with the ankle brachial index (ABI). This study will define the prognostic significance of the ABI for func-tional outcomes and cardiovascular morbidity and will describe changes in func-tional status over time among PAD patients. Our results will help determine whether the ABI should be used for targeted screening.